Island



(No Model.)

B. M. THOMPSON.

STEAM PLANT.

No. 593,703. Patented Nov, 16,1897.

UNITED STATES P TENT rrrcn.

DAVID M. THOMPSON, or PROVIDENCE, RHODE ISLAND.

STEAM PLANT. I

SPECIFICATION forming part of Letters Patent No. 593,703, dated November 16, 1897.

' Application filed March 29, 1897. Serial No. 629,766. (No model.)

To all whom it may concern.-

Be it known that 1, DAVID M. THOMPSON,

V of Providence, in the county of Providence and State of RhodeIsland, have invented a new and useful Improvement in Steam Plants; and I hereby declare that the following is a full, clear, and exact description of the sa-me,reference being had to the accom panying drawings, forming part of this specification.

In the generation of engine-power by the evaporation of water through the heat produced by the combustion of fuel, smoke, and

plete, the smoke may be of a yellow or lightbrown color, owing to the mineral matter, particularly sulfur, contained in the coal, but it will not be black, because it will not contain the coloring-matternamely, the unconsumed carbon. To secure the best results, it is essential that the combustion of the fuel in the furnace shall beperfect, and to insure this the volatile gaseous products of the combustion of the solid'fuel must be consumed before they enter the tubes of the boiler and become cooled.

The object of this invention is to secure the perfect combustion of all the carbon in the fuel. 7

Another objectof the invention is to utiliize the heat from the fire of one furnace while the gaseous products of combustion are passing to another furnace.

The invention consists in the peculiar and novel construction of two connected furnaces, as will be more fully set forth hereinafter.

Figure 1 is a vertical view of two vertical tubular steam-generators, showing the furnaces in section. .Fig. 2 is an enlarged sectional view of the open passage connecting the two furnaces, showing the water-grate in the same.

Similar letters of reference indicate corresponding parts in both figures.

In the drawings, A and B indicate two vertical tubular steam-boilers.

O is a flue connecting the upper part of the boilers witha flue indicated in broken lines and extending to the chimney.

D D are two dampers pivotally secured in the flue C, and E E are two rods, each of which is connected with a crank on the shaft of the dampers D D and by which the dampers may be operated.

F F are two central columns forming the water-legs of each boiler.

G G are two dome-shaped furnaces, one under each boiler. These furnaces are much higher than the ordinary boiler furnaces. They are inclosed by the curved and inclined fire-brick lining H H and are connected by the fire-brick-lined passage I. The fire-brick lining is inclosed with the cellular casing K,

containing water. The passage 1 has the water-grate L, supported on the pivots Z Z, which also form the inlet and outlet for the water which is forced through the passage formed in the'grate Ll As the construction of the grate forms no part of the present invention, the grate is referred to as the grate L and for the purpose of this invention may-be any of the ordin'aryforms of water-grate.

M is a door through which fuel is supplied to the grate L, and N a door for the removal of the ashes. g, g. indicate the grates of the furnaces, and h h the fire-doors.

I will now more fully describe the operation of. furnaces in connection with the steamboilers. When the fuel in the two furnaces has given up the volatile gases and the fire burns brightly. without smoke, the dampers D D are open and the heated products of combustion ascend through the tubes of the vertical boilers to the uptake and through the flue C tothe chimney inthe usual manner, and when it becomes necessary to supply fresh fuel to the furnaces they are fired alternately. If bituminous coal is used, one of the furnaces is supplied with the coal at a time when the other furnace has the bright fire which this fuel gives after the more volatile portions have been eliminated. Considering now that the right-hand furnace has reached that condition and the left-hand furnace requires to be fired, then, before firing, the grate L is placed into the position shown in solid lines in Fig. 1, coke is placed on the grate L' through the opening M, the high temperature of the fire-brick lining of the passage ignites the coke, the damper D of the left-hand boiler is closed, and the other damper D is opened wide. Coal is now thrown onto the fire of the left-hand furnace. The volatile carbon in the bituminous coal is liberated and rises into the upper part of the furnace, where, owing to the inward-curved dome-shaped firebrick lining, the heat is intense, so that the gases are maintained at a very high temperature. As the draft on the left-hand boiler is shut off, the gases do not enter the tubes of the boiler, and there is consequently but little boiler-surface to cool the gases. It will be observed on examining Fig. l of the drawings that the arched furnace extends a considerable distance above the passage I, the upper part of which is about half-way between the grate and the upper end of the furnace, and that this upper part of the furnace permits of the commingling and atomic mixture and expansion of the gases favored by the high temperature of this part of the furnace. As the draft on the left-hand boiler is closed and the draft on the right-hand boiler is wide open, the gases are drawn from the upper part of the left-hand furnace through the passage I and through the burning coke or similar fuel on the grate L into and over the bright fire of the right-hand furnace and, completely burned, pass through the tubes of the righthand boiler and from its uptake through the flue C to the chimney. During this time, which is not a long time, the boiler on the left is nearly as well supplied with heat and nearly as efficient as it is when the draft draws the heated products of combustion through the tubes of the boiler, because the heat of the furnace continues to rise up into the tubes. lVhen the right-hand furnace requires to be fired, the operation is reversed and the grate L is placed into the position shown in broken lines in Fig. 1. As the carbon is all burned, no black smoke is discharged from the chimney and greater economy in the consumption of fuel is secured.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. In a steam plant, the combination with two steam-boilers, of two furnaces connected by a horizontal passage and a grate in said passage, whereby, at the firing of one furnace, the products of combustion may be passed through the connecting-passage, ignited by fuel burning on the grate, and through the other furnace so as to consume the carbon in the products of one furnace and avoid smoke, substantially as described.

2. The combination of the following instrumentalities, viz: two vertical tubular steamboilers, flues connecting the boilers with a chimney, dampers in the flues, two furnaces having inclined curved sides, a passage connecting the lower half of the two furnaces, and a grate, pivotally supported in the passage, whereby the products of combustion of one furnace may be passed through the connecting-passage into the other furnace to secure the more perfect combustion of the fuel, as described.

In combination with two vertical tubular boilers, flues connecting the boilers with the chimney, and dampers in these flues for controlling the draft, of two furnaces, one under each boiler, said furnaces having each a grate of larger diameter than the boiler and inclosed bya fire-brick lining having inclined curved sides, a fire-brick passage connecting the two furnaces, a grate pivotally supported in the said passage and openings for supplying fuel to the furnaces and the grate in the connecting-passagegvhereby the products of combustion of one furnace may be carried through the passage, the other furnace and boiler by the draft to secure the more perfect combustion of the fuel, as described.

4. The combination in a steam plant with the two vertical tubular boilers A and B, having the flue O and the dampers D D for controlling the draft and the central column F F at the lower ends of the boilers, of the furnaces G G, one under each boiler, the grates g g and firingdoors h h and M, the inwardlycurved fire-brick linings II II, the passage I forming a connecting-flue between the lower part of the two furnaces, the upper part forming disconnected dome-shaped chambers, the grate L and the cellular casing K inelosing the lining of the furnaces and the passage; whereby the boilers may be alternately fired and the fuel more perfectlyconsumed, as described.

In witness whereof I have hereunto set my hand.

D. M. THOMPSON.

it11esses JOSEPH A. MILLER, JOSEPH A. hlILLER, Jr. 

